It is well known to provide a motor vehicle with a curtain airbag to protect an occupant of the motor vehicle from injury during an accident.
To achieve rapid inflation of such curtain airbags, a very large inflator may be required. Such large inflators are difficult to package on a vehicle and are so undesirable. Furthermore the curtain airbag is easily distorted during inflation and so it is possible for it to be pushed out through the window aperture if impacted against before full operating pressure is reached within the airbag.